I absolutely love solo travel.
I've done long weekend city breaks and, for longer periods, walking/yoga holidays. The activity holidays typically mean an optional group evening meal together which can be lovely. I have made lasting friendships from random people who attended the same interest course.
On an entirely solo break I like to book a room with a view, so that I can sit admiring the view, without or without a glass of something delicious in my hand. Tend to get up early, see what I want to see while it's relatively quiet. Have my main meal of the day at lunch time then plan on a drink/snack in the evening. Sometimes I do theatre etc events in the evening, so I am happy to eat out properly in the evening.
I've travelled enough for work to be comfortable on my own in restaurants and entertainment.
Mobile phone with kindle/audible combination and Bluetooth speakers provide a complete entertainment system at any time. (Remember the olden days when part of holiday prep was picking which books to take, now I take my whole kindle library).
The biggest difference is how likely I am to chat to people throughout the day. I'm much to old nowadays to worry about 'giving wrong signals ' and am happy to chat to anyone.
Usual precautions that are sensible anywhere. I would not finish a drink left unattended, would not broadcast my room number...
It's good to know about some things you can do if you want to, then have only yourself to please when you decide what to do all day and night.
Bliss.